Floating mine.



T. WRIGHTSON.

FLOATING MINE. APPLICATION FILED AuGJ. 1911.

1,298,142. I Patented Mar. 25,1919.

UNITED STATES) PATENT OFFICE. I

WBIGHTSON AND COMPANY,

LIMITED, 0F THORNABY-ON-TEES ENGLAND.

FLOATING MINE.

1,298,142, Specification of Application filed August 7,

To all whom it may concern:

Be it known that I, Sir THOMAS WRIGHT- son, Bart, a subject of the Kingof Great Britain, residing at Teesdale Iron Works, Thornaby-on-Tees,England, have invented a new and useful Improvement in Floating Mines,of which the following is a specification.

The object of this invention is to provide a mine or the like havingpreferably a positive buoyancy of variable amount with means whereby itis enabled to adjust its specific gravity to approximately that of thewater and thereafter to float freely at or about a predetermined depthbelow the surface.

My invention is illustrated by the accompanying drawing which shows moreor less diagrammatically a section of part of a mine.

The mine casing contains a supply chamher A partly filled with water.Within the casing is mounted a pump B which can be continuously drivenby an electric motor C operated by a battery D, the motor being startedbefore the mine is placed in the water by means of the switch E. Thepump delivers water from the chamber A to an intermediate chamberpreferably in the form of an accumulator F, the delivery pipe of whichis provided with a check valve G and leads to a valve casing H in whichworks a valve composed of two pistons I, J. This valve is controlled bya solenoid K energized by a battery L when its circuit is closed througha switch M controlled by a diaphragm m exposed to the external pressure.The valve casing H has opening from it two pipes of which the one Nleads to a chamber 0 having a flexible wall P exposed to the'pressure ofthe surrounding water but shielded for the greater part of its surfacebyoa guard Q, while the other R opens into the interior of the casing AS is a blow-ofi valve.

When the mine is put into the water, the pump B pumps water from thebottom of the casing A into the accumulator F. The mine having sunk to apredetermined depth, the switch M is closed by the pressure of the waterand the solenoid K raises the valve I, J, so that water passes from theaccumulator F through the casing and pipe N to the chamber 0, distendingthe flexible wall P and therefore increasing the Lett r P en PatentedMar. 25, 1919.

1917, striai'misasei.

displacement of the mine which accordingly rises. The consequent fall inthe external pressure causes the switch M to open, the valve drops tothe position shown, the piston I stopping the flow of water from theaccumulator and the piston J uncovering the pipe B, so that water in thechamber 0 flows back through the pipe N, casing H and pipe B, into theinterior of the casing A, thus diminishing the displacement of the mine,which accordingly sinks again and the operations are repeated; the minethus alternately rises and falls for a short distance so long as themotor C continues to work.

What I claim is 1. In a floating mine having a liquid supply chamber,the combination of an expansion chamber connected with the supplychamber, an intermediate chamber connected with the supply chamber andthe expansion chamber, and means for transferring liquid from theintermediate chamber to the expansion chamber and from the expansionchamber to the supply chamber.

2. In a floating mine having a liquid supply chamber, the combination ofan expansion chamber connected with the supply chamber, an intermediatechamber between the liquid supply chamber and the expansion chamber, apump for transferring liquid from the supply chamber to the intermediatechamber, valve mechanism controlling the passage of liquid from theintermediate chamber to the expansion chamber and the passage of liquidfrom the expansion chamber to the supply chamber.

3. In a floating mine, the combination of .a chamber having a flexibleexterior wall, an accumulator, a pump adapted to force water from theinterior of the mine into the accumulator, means for driving the pump, avalve controlling the flow of water from the accumulator to the chamberand from the chamber to the interior of the mine and means adapted to beactuated by the pressure of the water surrounding the mine forcontrolling the valve.

4. In a floating mine, the combination of a chamber having a flexibleexterior wall, an accumulator, a pump adapted to force water from theinterior of the mine into the accumulator, means for driving the pump, avalve casing, a pipe leading from the accumulator to the casing, asecond pipe leadingffomkhe casin to fih'eehgfibef; ii; Watersurroundlngihe'mine ifo energizing third pipe leading from the easing tQt htS *thes'eleneid, r interior-6f rihe mi ile, a valveatiapfefi to.uIthi li i'dsfesti'mnyithat the second *fiipe commnnicafion wfl1 e as myi'nvemfiqnl hwv lafim thel fnregoing 1 0 l'g'neglmy-name this solenoidadapted to move the valve' ethd' ,7 s '7 means controlled 'by thepressure 0f.thef THOMAS'WB IGHTSON. Cepieeofthi patent-2' nias ebtainedfqg fiye eente each, byjaddiess ingtthe"flemmiegio er of Idtnts,

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